U.S. Pat. No. 8,899,194 has disclosed a piston for a two stroke engine which operates with advanced scavenging, which piston has piston pockets which serve to connect an air inlet which opens at the cylinder bore to transfer windows of transfer channels. Air from the air inlet is advanced in the transfer channels via the piston pockets. A multiplicity of deepenings are provided on the piston skirt of the piston.